July 11, 2012

Tumor Cells In Mice Killed By Mediterranean Weed Drug

Connie K. Ho for - Your Universe Online

While grenades have been mentioned in situations related to the military, they have never been mentioned in scientific research dealing with cancer. That is, until now. A new innovative drug by researchers at the Johns Hopkins Kimmel Cancer Center, in collaboration with Danish scientists, works like a “molecular grenade”; it can move through the bloodstream until activation by specific cancer proteins.

The drug is made from a weed-like plant that has demonstrated its ability to destroy cancer and direct blood sources, working and safeguarding healthy blood tissues and vessels.  The drug, G202, is made from Thapsia gargancia, a weed that grows in the Mediterranean area. The plant produces thapsigargin, a product that has been known to be toxic to animals.

The investigators stated that, through laboratory studies, they tested a three-day course of drug G202. Within 30 days, the drug can decrease the size of human prostate tumors found in mice to about 50%. When compared to chemotherapy drug docetaxel, G202 outperformed it and reduced seven of nine human prostate tumors in a 21-day period.

Apart from the study done with tumors, G202 was able to produce regression in illness like bladder cancer, breast cancer, and kidney cancer. The findings are presented in a recent issue of the journal Science Translational Medicine.

"Our goal was to try to re-engineer this very toxic natural plant product into a drug we might use to treat human cancer," commented lead study author Dr. Samuel Denmeade, professor of oncology, urology, pharmacology and molecular sciences, in a prepared statement. "We achieved this by creating a format that requires modification by cells to release the active drug."

In the project, scientists disassembled thapsigargin and chemically modified it. The drug was injected into mice and researchers saw how it would travel through the bloodstream until it arrived at the site of cancer cells. The protein prostate-specific membrane antigen (PSMA) would then be released by cells in tumors that were based in the prostate and other areas and activate cell-killing agents into the tumor and blood vessels. The G202 was able to prohibit the function of protein SERCA pump. This protein, in particular, was important for cell survival and kept the levels of calcium at a correct level. With the drug focused on the SERCA pump, it would be difficult for the cells to stay alive and the tumor cells would lower its resistance to the drug.

In moving forward with the study, the Johns Hopkins investigators have already performed a phase I clinical trial in testing the safety of the drug. They have successfully treated 29 patients who have advanced stages of cancer.

"The exciting thing is that the cancer itself is activating its own demise," commented senior study author John Isaacs, professor of oncology, urology, chemical and biomedical engineering at Johns Hopkins, in the statement.

The University of Wisconsin and the University of Texas, San Antonio also participated in the trial. The researchers are planning to conduct a phase II trial to test the drug with patients who have liver cancer or prostate cancer.